1. Field
One or more embodiments of the present disclosure relate to an apparatus and method for checking whether a sub unit is connected to a main controller.
2. Description of the Related Art
Electronic devices may each include a plurality of units. The plurality of units are connected to one another but may also be disconnected from one another. Thus, there is a need to check which units are disconnected from each other among the plurality of units.
A pull-up resistor and a pull-down resistor are elements that prevent units from being floated when no voltage is applied to the plurality of units. The pull-up resistor is used to apply a high voltage to a unit, and the pull-down resistor is used to apply a low voltage to a unit.